An important function of the lung is the transport of material from the respiratory airways to the pharynx. The role of ciliary activity in this transport has been validated experimentally both in vitro and in vivo. However, a direct method that can be eventually implemented for clinical use to measure frequency and coherency of ciliary beat in situ has not been developed. During the last two years, we have developed and validated a unique method to precisely measure frequency and coherency of ciliary beat using laser light scattering spectroscopy. This project is intended to undertake the development, evaluation and fabrication of a new instrument (a fiber optic laser spectrometer-bronchoscope) to measure frequency and coherency of ciliary beat in situ. This development will provide a unique, simple, objective and reliable method to study ciliary function of the lung in situ.